High pNIC error rate detected on ESXi host after upgrading ESXi host to version 8.0 u3

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi hosts report the error: "RX/TX Pause rate reaches ####% on vmnic#".
• Values typically exceed 100% (e.g., 2000%, 5000%).

• esxcli network nic stats get -n vmnic#

   shows zero or near-zero "Total receive errors" and "Total transmit errors" despite the alarm.
• No performance or latency issues occur on the vSAN network.
• Issue appears on ESXi 8.0.3 build-24585383 or higher.

 NIC statistics for vmnic1:
      Packets received: 3465641940
      Packets sent: 4147299144
      Bytes received: 6955624733129
      Bytes sent: 17914684133404
      Receive packets dropped: 13
      Transmit packets dropped: 0
      Multicast packets received: 15475950
      Broadcast packets received: 289350
      Multicast packets sent: 247061
      Broadcast packets sent: 12914
      Total receive errors: 0
      Receive length errors: 0
      Receive over errors: 0
      Receive CRC errors: 0
      Receive frame errors: 0
      Receive FIFO errors: 0
      Receive missed errors: 0
      Total transmit errors: 0
      Transmit aborted errors: 0
      Transmit carrier errors: 0
      Transmit FIFO errors: 0
      Transmit heartbeat errors: 0
      Transmit window errors: 0

Privstats:
      RxXon: 0
      RxXoff: 0
      TxXon: 15
      TxXoff: 64

Environment

vSphere ESXi 8.0.3
vSphere ESX 9.0

Cause

The vSAN network alarm calculation incorrectly reports network error rates, allowing them to exceed 100%. This is a cosmetic issue and does not indicate a hardware failure.

Resolution

Fixed in release ESXi 8.0 Update 3h (Build 25067014) and higher. See Download Broadcom products and software for steps to download this release.

For vSphere 9.0, this issue is resolved in vSphere 9.0 P02 and higher.

Workaround: If an upgrade is not immediately possible, disable the alarm in the vCenter UI:

1. Select the affected ESXi host.
2. Navigate to Configure → Alarm Definitions.
3. Locate the alarm: “High pNic error rate detected. Check the host's vSAN performance view for details.”
4. Select Disable.

Additional Information

Alarm about high pNIC error rate being detected